1. Technical Field
This disclosure relates to computer networking. More specifically, this disclosure relates to methods and apparatuses for load balancing between wide-area network (WAN) optimization devices.
2. Related Art
The enterprise network has become a critical part of an organization's information technology infrastructure. Enterprise networks often include a WAN that interconnects offices that are distributed over a large geographical area. Many enterprise networks include one or more data centers that host computers to provide critical services (e.g., email, file sharing, etc.) throughout the organization. Improving performance of the enterprise network is important because it improves productivity, which in turn increases profitability.
Some enterprise networks use WAN optimization devices to improve network performance. WAN optimization devices optimize network traffic to improve WAN performance in reading and/or writing data over a network. Some WAN optimization devices monitor users' network traffic to attempt to predict data likely to be requested by users. This predicted data is prefetched over the WAN and cached by the WAN optimization devices at the users' respective network locations, so that this data can be quickly accessed by users if requested. WAN optimization devices also typically compress data (e.g., by performing de-duplication) for communication over the WAN. The WAN optimization devices' prefetching, caching, and compression masks the bandwidth and latency limitations of WANs from users.
WAN optimization devices may operate singly or in pairs at each side of a WAN connection to optimize network traffic. WAN optimization devices are referred to in the art by many different terms, including, but not limited to, transaction accelerators, WAN optimizers, WAN optimization controllers (WOCs), wide-area data services (WDS) appliances, WAN traffic optimizers (WTOs), and protocol accelerators or optimizers.
Additionally, techniques for optimizing network traffic to improve network performance in reading and/or writing data over a network are referred to in the art by many different terms, including, but not limited to, WAN acceleration, transaction acceleration, transaction pipelining, protocol pipelining, request prediction, application flow acceleration, and protocol acceleration. In this disclosure, the term “WAN optimization device” is used to refer to such devices and applications and “WAN optimization” is used to refer to such techniques.